Newly manufactured vehicles, after production, may be parked on a production plant parking lot before they are delivered to dealerships for sale. These vehicles may also be filled with low octane fuels and may be parked for longer durations at the production plant parking lot, and later, at a dealership lot before they are sold. As such, lower octane fuels can cause pre-ignition events during engine operation resulting in engine degradation. Pre-ignition events may also be triggered by aggressive driving such as driving that can occur when moving vehicles for short distances around production plant parking lots. In addition to pre-ignition, spark plugs in engines in the new vehicles may also be susceptible to degradation. As an example, spark plugs may experience fouling due to the presence of rich combustion conditions when engines are cold started. Further, as engine run times may be shorter when newly manufactured vehicles are moved around the production plant parking lot, carbon deposits on the spark plugs may not be burned off leading to fouling of the spark plugs. Thus, engine degradation in newly manufactured vehicles may occur due to pre-ignition as well as spark plug fouling.
Once the newly manufactured vehicle is delivered to a dealership, conditions such as short drive cycles, aggressive driving, etc. may be reduced. Further, the vehicle at the dealership may be filled with a fuel of higher quality for improved performance. Therefore, remedial actions taken to reduce spark plug fouling and pre-ignition before delivery of the new vehicle to the dealership may degrade vehicle performance and affect drivability once the new vehicle is delivered to the dealership.
The inventors, herein, have recognized the above issue and identified an approach to at least partially overcome the issue. In one example approach, a method comprises, during a pre-delivery phase of a vehicle including an engine, operating the engine with a first setting for a parameter in a pre-delivery calibration, adjusting the first setting of the parameter responsive to pre-ignition, and during a post-delivery phase of the vehicle, operating the engine with a second setting for the parameter in a post-delivery calibration. In this way, different settings for engine parameters may be used to address pre-ignition during each of the pre-delivery and post-delivery phases of the vehicle.
For example, a boosted engine in a newly manufactured vehicle may be operated with a pre-delivery calibration during a pre-delivery phase. The pre-delivery phase may include a phase between production and delivery to a dealership. In another example, the pre-delivery phase may include a mileage that is lower than a pre-determined threshold. The pre-delivery engine calibration may be activated at a plant following vehicle production and may last until the completion of the pre-delivery phase. The pre-delivery engine calibration may include a first setting for a parameter wherein the parameter may be one of air/fuel ratio, engine load, spark timing, etc. In one example, the pre-delivery calibration may include operating the boosted engine with the first setting for a parameter such as air/fuel ratio. As such, the first setting for air/fuel ratio may include a leaner than stoichiometric air/fuel ratio setting in order to reduce spark plug fouling. In another example, the parameter may be engine load and the first setting for engine load may be an engine load with a less conservative limit. This first setting for the parameter, e.g. air/fuel ratio, engine load, etc., in the pre-delivery calibration may be adjusted in response to pre-ignition. As an example, combustion may be enriched by a first amount of richness so that the air/fuel ratio is richer than stoichiometric in response to pre-ignition conditions. In the example of the parameter being engine load, a more conservative load limit may be enforced in response to pre-ignition.
Once the newly manufactured vehicle is delivered to the dealership, an operator may deactivate the pre-delivery engine calibration and the engine may be operated in a post-delivery calibration. Accordingly, a second setting may be used for the parameter in the post-delivery engine calibration. In the example of air/fuel ratio, the second setting for air/fuel ratio may be a stoichiometric setting and the engine may be operated with a stoichiometric air/fuel ratio in the post-delivery phase. In the example of the parameter being engine load, the second setting may include operating with no limits on engine load in the post-delivery calibration. The second setting for an engine parameter may be adjusted in response to pre-ignition in a different manner in the post-delivery phase relative to the adjustment of the first setting in the pre-delivery phase. As an example, in response to pre-ignition, the second setting for air/fuel ratio may be modified with a different gain relative to the adjusting of air/fuel ratio in the pre-delivery phase. Specifically, the second setting of air/fuel ratio may be adjusted to provide a second richer air/fuel ratio responsive to pre-ignition. A second amount of richness may be delivered to achieve the second richer air/fuel ratio. Further, the second amount of richness may be smaller than the first amount of richness provided in the pre-delivery phase in response to pre-ignition.
In this way, an engine in a newly manufactured vehicle may be operated with different calibrations to control pre-ignition in the pre-delivery phase and the post-delivery phase. The first setting for an engine parameter in the pre-delivery calibration may initially address spark plug fouling. The first setting may be adjusted more aggressively in the pre-delivery phase to control pre-ignition conditions in the engine. By employing more aggressive controls, degradation of the engine due to aggressive driving and short driving cycles may be reduced. The post-delivery calibration, on the other hand, may enable improved engine performance and fuel efficiency. Herein, engine settings may be adjusted less aggressively in response to pre-ignition in the post-delivery phase. Overall, by using two distinct calibrations, engine durability may be improved in the pre-delivery phase and drivability may be enhanced in the post-delivery phase.
It should be understood that the summary above is provided to introduce in simplified form a selection of concepts that are further described in the detailed description. It is not meant to identify key or essential features of the claimed subject matter, the scope of which is defined uniquely by the claims that follow the detailed description. Furthermore, the claimed subject matter is not limited to implementations that solve any disadvantages noted above or in any part of this disclosure.